Bridge



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BRIDGE.

No. 498,994. Patented June 6, 1893.

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No. 498,994. PatentedJune 6, 1893.

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BRIDGE.

PatentedJune 6, 1893.

Unirse STATES PATENT Ormea.

CHARLES LOUISSTROBEL, OF CHICAGO, ILLINOIS.

BRIDGE.

SPECIFICATION forming part of Letters Patent No. 498,994, dated J une 6, 1893.

Application filed April 26,1892.

To all whom it may concern:

Be it known that I, CHARLES LoUIs STRO- BEL, of Chicago, Illinois,have invented a certain new and useful Improvement in Bridges, of which the following is a specification.

The object of my invention is to make a simple, economical, efcient and durable iron or steel bridge, of the kind usually called a through bridge; and the invention consist-s in the features and combinations hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a broken plan view of my improved bridge; Fig. 2 a cross sectional View of the bridge taken in line 2 of Fig. l; Fig. 3 a broken plan View of one end of the bridge showing a modified form of construction; Fig. 4. a cross sectional view of the bridge, taken in line e of Fig. 3; Fig. 5 a side elevation of the bridge shown in Figs. l and 2; and Fig. 6 a side elevation of the bridge shown in Figs. 3 and 4.

A are girders composed of I-beams, a braces securing the inner girders together, and a bolts securing each outer girder to its adjacent inner one; B cross ties extending between the outer girders and their adjacent inner ones and supported on the iianges thereof; C longitudinal timbers extending across the cross ties and forming guard rails; and D plates and anchors securing the ends of the bridge to their respective abutments.

In one form of through bridge, as now constructed, the iioor consists of iron or steel floor beams and stringers, Wooden cross ties being placed upon the stringers. In another form, the cross ties are supported upon the lower flanges of the girders, two lines of girders only being used. The objection to the first form is that it is expensive, and to the second thatthe replacement of the cross ties is difficult and the lower tlanges of the girders are overstrained.

The object of my invention is to provide a more simple and economical plan of bridge, which shall be free from these objectionable features.

In making my improved through bridge, I use four girders, composed of single or compound I-beams, extending parallel with each other, the inner ones being firmly braced or Serial No. 430,774. (No model.)

secured together, and the outer ones firmly bolted thereto. As shown, the inner lines of girders are connected by means of diagonal bars riveted tothe beams. The inner lines being braced in this way, so that their width does not exceed the width of a railroad car,

they are easily shipped, and all the work of riveting can be done at the mill where the girders are rolled, thus obviating the necessity of doing any riveting in the field. This construction secures ample lateral stiffness for the bridge. As shown, the two outer lines of girders are connected to the inner lines by ordinary bolts. If desired, these bolts may be made to extend entirely across from one outer girder to the other. In this case they will ordinarily pass th rough the inner girders without being attached thereto. The cross ties rest upon the flanges of the beams. As four supports are thus provided for each pair of cross ties, the load upon the Iianges is reduced to a minimum. The distance from top of girder to top of tie is preferably made five or six inches, so that there may be no interference between a snow plow and the center girders. The upper iianges of the four lines of girders form, with the two lines of rails, six lines of metallic skids, which will permit cars to slide over the bridge in comparative safety in case of an accident-such as the breakage of an axle or wheel. The depth from base of rail to bottom of bridge is less than would be required for a through bridge with iron floor beams and stringers,4

which is the type now generally used. The width of these bridges from side to side is about the same as would be required for 'deck bridges, so that if a second track is to be added at any time in the future, this track may be placed at the normal distance to one side of the first track, whereas in case of through bridges of the other kind, this distance would have to be increased.

In Figs. 3 and 4. I have shown a modified form of bridge, in which two sets of I-beams are used, one placed on top of the other called compound beams. The object of this is to reinforce the girders, orprovide a sufficiency of lstrength in cases of long spans. When the bridge is constructed in this Way, the

IOO

beams may be secured together and the cross tics placed in position, as above described. It Will generally not be found necessary to use diagonal bracing with the lower beams, ordinary I-beam separators being su'llicient.

As the essence of my invention consists (First) in constructing a throughfbridge in which there shall be four lines of girders; and (second) in constructing a through bridge 'in which the depth from base of rail to bot- 2o angles.

I claim- 1. A through bridge comprising four lines of girders, the inner lines being firmly and securely braced or secured together by means of diagonal bars bolted or riveted thereto, and each outer line firmly secured to its adjacent inner line by bolts passing through the same at right angles, substantially as described.

2. A through bridge comprising outer and inner girders, and cross ties between the girders resting upon the iianges thereof, whereby the depth from base of rail to bottom of bridge is rendered comparatively small,substantially as described.

CHARLES LOUIS STROBEL.

Witnesses:

EPHRAIM BANNING, SAMUEL E. I-IIBBEN. 

